Question: What is the secret police of Lavrentiy Beria's military branch?
Paraphrase: What is the mystery police of Lavrentiy Beria's military branch?
SPARQL (Wikidata):  select distinct ?obj where { wd:Q141829 wdt:P241 ?obj . ?obj wdt:P31 wd:Q214183 } 
Answer: NKVD